WATER. 



meUiod employed : and all that can be done with precifion 

 is to eftimate the elements, and then to exhibit their binary 

 combinations, according to whatever may be the moll pro- 

 bable view of the real compofition. 



The method propofed by Mr. Kirwan, formerly al- 

 luded to, confifts in determining, chiefly by tefts, the 

 quantity of the different faline fubilances prefent. But the 

 complicated nature of many of the formulae, bcfide the very 

 principle of the method itfelf, being liable to moft of the 

 objeftions above urged by Dr. Murray againft that in com- 

 mon ufe, render its' application difficult, and refults uncer- 

 tain. Upon the whole, therefore, we have no hefitation in 

 faying, that we confider Dr. Murray's views and methods 

 as by far the belt, and moft likely to le.id to corrcft con- 

 clufions, that have yet appeared, and which may be ftatcd 

 in few words, as follows : 



" Determine by precipitants the weight of the acids and 

 bafes prefent in a mineral water. Suppofe them united in 

 fuch a manner that they (hall form the moft foluble falls : 

 thefe falls will conftilute the true faline conftituents of the 

 water under examination." 



Dr. Murray illuftrates his method of procedure by fup- 

 pofing, as an example, a water found, by the ufual tefts, 

 to contain the carbonates, fulphates, and muriates of lime, 

 magnefia, and foda. The water is to be reduced by eva- 

 poration as far as can be done, without occafioning any 

 fenfible precipitation or cryftallization. A faturated folu- 

 tion of muriate of barytes is then direfted to be added as 

 long as any precipitate falls, and no longer. This precipi- 

 tates the whole of the fulphuric and carbonic acids, and the 

 carbonate of barytes is to be feparated from the fulphate by 

 diluted muriatic acid. Add to the refidual liquor a folution 

 of oxalate of ammonia as long as any turbid appearance is 

 produced. By this the whole of the lime is feparated. 

 The oxalate of lime is to be calcined, and converted into 

 fulphate of lime, from which the quantity of pure lime may 

 be readily eftimated. The next (lep is to precipitate the 

 magnefia ; and for this purpofe. Dr. Murray recommends a 

 modification of Dr. WoUafton's procefs. This confifts in 

 adding, firft, a folution of neutral carbonate of ammonia, 

 and afterwards a ftrong folution of phofphoric acid, or 

 phofphate of ammonia ; taking care to leave an excefs of 

 the carbonate of ammonia. By thefe procefTes, the whole 

 of the magnefia is obtained in the ftate of triple phofphate, 

 and its quantity can be readily eftimated. Muriate of foda 

 now remains in folution, and its quantity can be obtained by 

 evaporation. As a check, however, to the different pro- 

 cefTes, it may be proper to afcertain the quantity of muriatic 

 acid prefent by means of the nitrate of filver. 



If alumina, filica, or iron be prefent, they are beft fepa- 

 rated by diftinft procefTes, in the manner formerly de- 

 fcribed. 



Laftly, Dr. Murray recommends that the refults of an 

 analyfis be ftated in three modes : 'ift. The quantities of the 

 acids and bafes ; idly. The quantities of the binary com- 

 pounds, as inferred from the principle that the moft foluble 

 compounds are the ingredients ; and 3dly, The quantities 

 of the binary compounds, fuch as they are obtained by 

 the ufual modes of analyfis. The refults will be thus pre- 

 fented in every point of view. As an inftance of this 

 method of ftating the refults of an analyfis, we refer our 

 readers to what we have faid on fea-'water in the prefent 

 article. 



Mineral Waters, artificial Preparation of. — Chemiftry had 

 no fooner developed the compofition of mineral waters, than 

 it fuggefted methods of preparing them artificially. Ac- 

 cordingly, Bergman and others have given many formulae for 



this purpofe, fome of which approach the truth, while 

 others are very imperfeft. When the compofition of a 

 water is very fimple, nothing more is required to form it 

 artificially than to know the nature and quantity of the 

 faline fubftances prefent, and to diffolve fimilar quantities of 

 the fame faline fubftances in the fame proportion of water. 

 In the earlier periods of chemical inveftigation, before the 

 nature of gafeous fubftances was underftood, no attempts 

 of courfe could be made to imitate the important clafs of 

 waters which derive their chief properties from the prefence 

 of fuch fubftances ; but chemifts no fooner became ac- 

 quainted with the nature of gafes, than they began to devife 

 methods of imitating thefe alfo ; and artificial carbonated 

 waters have been long fince prepared as an article of com- 

 merce, under the name oifoda ivater, fuperior in point of im- 

 pregnation to any acidulous waters known. See Pyhmont. 



It is true that there are fome inftances of natural chemical 

 folution, which art has not even yet been able to imitate. 

 Of this kind is the folution of filex, wliich occafionally oc- 

 curs in mineral waters. It is doubtful, however, if this 

 earth is capable of exerting any falutary effedls on the animal 

 economy ; and, therefore, we have little occafion perhaps 

 to regret our inability to effedt its folution. Another defetl 

 in the formation of artificial mineral waters is, that many of 

 the more important ones cannot be obtained in large quan- 

 tities for bathing, &c. without fo great a degree of expence 

 and trouble, as to entirely preclude their ufe. 



On the other hand it feems plaufible, in theory at leafl, 

 that we can improve upon the compofition of many mineral 

 waters. Thus, many mineral waters contain ingredients, 

 which, either from the minutenefs of the proportion in which 

 they exift, or from their inert nature, may be deemed as 

 fuperfluous, or in fome inftances as injurious. Again, 

 others contain their aftive ingredient in fuch fmall quantities, 

 as to require an inconvenient bulk of the water to produce 

 the defired effeft : all which defefts may be remedied in the 

 artificial preparation, by leaving out the ufelefs or noxious 

 matter, and increafing that in which the proper medicinal 

 virtue refides. Befides thefe advantages alfo, we have it in 

 our power to form new and valuable compounds, which are 

 no where to be met with in a natural ftate. 



The firft itep to the artificial formation of a mineral 

 water is, of courfe, to know the exaft compofition of the 

 water we would imitate. Many of the ingredients, how- 

 ever, obtained from mineral waters by the ufual modes of 

 analyfis, are very little foluble in water : fuch, for example, 

 are the fulphate and carbonate of lime, &c. which we Ihould 

 attempt in vain to diffolve direftly in water. Other modes, 

 therefore, mull be devifed for this purpofe ; and Dr. Mur- 

 ray's views of the compofition of mineral waters in general 

 will enable us to effeft our objeft, in moft inftances, very 

 readily and completely, as the following example will 

 (hew. 



Suppofe we wifhed to imitate the Seltzer water, an 

 Enghfh pint of which, according to Bergman's analyfis, 

 contains, as before mentioned, of 



Cub. Inches. 

 Carbonic acid - - - - 17 , 



Carbonate of lime 

 Carbonate of magnefia 

 Carbonate of foda 

 Muriate of foda 



Grains. 



3 

 5 



4 

 17-5 



29.5 



Of 



